Selective detection and bio-imaging of Pd2+ with novel ‘C–CN’ bond cleavage of cyano-rhodamine, cyanation with diaminomaleonitrile

Abstract

A new rhodamine based chemosensor, cyano-rhodamine, has been designed and synthesized with a green approach which shows a specific 'C-CN' bond breaking with the action of the Pd(2+) ion to produce the specific color and fluorescence of rhodamine 6G itself in solution and in HeLa cells.

Fluorometric imaging methods for palladium and platinum and the use of palladium for imaging biomolecules

“…67 Goswami and coworkers disclosed a colorimetric and fluorimetric bio-imaging method for palladium using the nitrilebased chemodosimeter 4. 39 The cyano group of 4 disrupts the conjugation system of rhodamine 6G. Addition of Pd(II) removed the cyano group from chemodosimeter 4, restoring the fluorescence at 555 nm upon excitation at 505 nm (Scheme 3).…”

“…Addition of Pd(II) removed the cyano group from chemodosimeter 4, restoring the fluorescence at 555 nm upon excitation at 505 nm (Scheme 3). 39 This method also has utility as a colorimetric detection method based on the color of rhodamine 6G. 39 Scheme 1 Exposure of 1 to palladium releases fluorescent Pittsburgh Green.…”

“…39 This method also has utility as a colorimetric detection method based on the color of rhodamine 6G. 39 Scheme 1 Exposure of 1 to palladium releases fluorescent Pittsburgh Green. 65 Nitrile 4 was tested in HeLa cells for membrane permeability and utility as a bio-imaging reagent for palladium.…”

RBAP, a Rhodamine B-Based Derivative: Synthesis, Crystal Structure Analysis, Molecular Simulation, and Its Application as a Selective Fluorescent Chemical Sensor for Sn2+

“…On the basis of the spirolactam/ring-opened amide equilibrium of rhodamine, several fluorescence-based sensing systems for metal ions have been developed. Most of the reported sensors based on rhodamine B derivatives are fluorescent chemosensors for the detection of Pb 2+ , Cd 2+ , Cu 2+ , Fe 3+ and Hg 2+ ions [21,22,23,24,25,26,27,28,29]. Unfortunately, to the best of our knowledge, only a few rhodamine B-based chemosensors have been reported for tin ions [30].…”

Metal-free three-component cyanoalkylation of quinoxalin-2(1H)-ones with vinylarenes and azobis(alkylcarbonitrile)s

“…3 However, these methods use expensive and complex catalysts of metals such as ruthenium, 4 rhodium, 5 or palladium 6 and also toxic cyanide sources, 7 namely KCN, NaCN, TMSCN, CuCN, and Zn(CN) 2 . Although a few mild cyanating agents such as diaminomaleonitrile, 8 aryl cyanates, 9 tosyl cyanide, 10 cyanobenziodoxole, 11 aryl(cyano)iodonium triflates, 12 N -cyano- N -phenyl- p -toluene sulfonamide, 13 cyanocarbonyls 14 and Zhdankin's reagent 15 efficiently drive C–H cyanation reactions, these cyanide sources are generally prepared from highly toxic precursors. Hence, a more affordable and commercially available nitrile source is in high demand.…”